Fork won’t fit snuggly into frame

[RayF]

Serviced my fork for the first time on my MTB
But can’t get the fork to fit back snuggly into the bottom part of the frame (the space is too large- see pic) - beginner mistake clearly and as there doesn’t seem to be many things that I’m doing in the wrong order.
The headset is a semi integrated with caged bearings (see pic). The parts on the bottom of the fork tube are the crown (which I didn’t touch) a plastic ring, a metal support ring and the caged bearings (see pic). I first slide the bearings into the frame’s bottom cup so they fit snugly, then I place the metal ring . Here is where I think something is wrong. I would expect this metal ring to sit flush within the frame after which I could push the rest of the fork tube up into the frame leaving just the crown to be visible but it doesn’t. So that plus the plastic ring and the crown that are all outside the frame create way too much space. I assume I should not need to push very hard or bang all this in with a rubber mallet? - thanks for your help!

 

[iluvmybike]

That plastic bit doesn't look like it belongs there

 

[RayF]

Photos 3 was taken after I took the fork out (so I would remember the order). The order is also shown on photo 1- hence my total confusion as to why all these don’t fit flush when I put the fork back

 

[Cycleops]

You've got the order of the spacers/bearings wrong, just fiddle about with them until it all fits. You might have some in upside down.

 

[Racing roadkill]

You’ve got the sort of headset where the cups press into the frame, and the bearing cages ( with the bearings in) sit in the cups. There will be a crown race of some description, on which the bearings run and if it’s anything like the one I’ve just replaced on my Hybrid, ( FSA numbed 10 ) the crown race is just a bit of thin, race shaped plastic. There may be a metal crown race already on the fork, If there is, remove it. Pack the cups and bearings with grease, and the plastic race should stick in place when you lower the frame onto the forks. It’s not a great design, but it’s cheaper than the traditional alloy race that you used to get. You’ve also got the bearings on top of the cup, they go inside it ( so you’ve got them on the wrong side of the cup ). Lift the caged bearings off of the cup, press the cup into the frame and put the bearings inside the cup. They will try and fall out, so stick them in with grease, then put the race over them, then get someone to hold the fork, as you lower the frame onto it, and keep your fingers under the race until the last second.

 

[RayF]

Thanks for the long response. I haven't had a chance to work on the bike but a few things confuse me a bit in your message. Not sure why i need to remove the fork crown - I'm just putting back a bearing system that was there and working fine (I removed the fork for an oil service) so assume the crown stays as is.
'press cup into the frame' ? there is already a cup in pressed in to the frame (it's a semi integrated system) so I assume the bearings go straight into that . It's the metal ring under the bearings in photo 1 that is my real problem - i don't know what this part is for and that is what is protruding.... will fiddle around with it some more - cheers

 

[Racing roadkill]

Thanks for the long response. I haven't had a chance to work on the bike but a few things confuse me a bit in your message. Not sure why i need to remove the fork crown - I'm just putting back a bearing system that was there and working fine (I removed the fork for an oil service) so assume the crown stays as is.
'press cup into the frame' ? there is already a cup in pressed in to the frame (it's a semi integrated system) so I assume the bearings go straight into that . It's the metal ring under the bearings in photo 1 that is my real problem - i don't know what this part is for and that is what is protruding.... will fiddle around with it some more - cheers

The “metal ring under the bearings” looks like a cup to me. The bearings go inside it, you’ve got them sitting on top of that cup, if I’m seeing the photo right. If the crown race was working before, it should still be okay, providing you have got the right headset. Those aren’t fully integrated headset bearings in the photo. You’ve got two metal cups that press into the frame there. One at the top, one at the bottom of the head tube. The bearings go in the cups once they are pressed into the frame. You should have a centering ring which goes into the top bearing / cup assembly as well, and a cover for the top bearing / cup assembly. A semi integrated system is a sealed integrated / cartridge bearing and cup ( angled contact bearing, or ACB) which presses into the frame, that’s not what you have in the photo. It looks like you have put the top cup on top of the fork crown, the bearings on top of the cup, then tried to put the fork back into the frame, with a cup in the bottom of the head tube ( which is in the right place).

 

[RayF]

Thanks- issue resolved after speaking to a bike mechanic. Maybe just semantics but he did refer to this as a semi integrated system (ie the cups are already pressed in the frame ... they can be removed with a tool - and the bearings go into these directly )
The metal ring mentionned before (which is not a cup but a cover) actually belongs to the top part of the headset (on top of the bearings) . At the bottom it’s just bearings into the frame’s cup followed by the plastic ring and the firm’s crown to create the final seal.
thanks again - I realise it’s not always easy to diagnose things with photos!